Coded signal transmission system

ABSTRACT

Coded signal transmission equipment is disclosed wherein a preselected train destination signal comprising a six-bit code signal coded to correspond to anyone out of 0 to 49 and/or a preselected train length signal comprising a six-bit code signal coded to correspond to anyone out of 50 to 59 are sent between a train vehicle and a selected wayside location. These numbers are the result of the particular coding technique employed. In general it is desired to send two coded signals and to separate those signals within the signal receiving equipment in a fail safe manner. For this purpose there is provided a wayside located signal receiving equipment which includes a signal register in which both the destination signal and the length signal are serially stored and shifted by a suitable shift control signal. A predetermined logic circuit arrangement is operative with a selected portion of the shift register to sense when a predetermined one of said signals is stored in said portion of the register to indicate that the register at that time is fully loaded and properly oriented. The desired coded signals can then be read out and utilized to indicate the train destination and/or the train length as may be desired. A similar technique is employed to transmit coded vehicle performance signals back to the train vehicle.

United States Patent [72] Inventor Robert C. Hoyler Monroeville, Pa.[21] Appl. No. 730,572 [22] Filed May 20, 1968 [45] Patented June 1,1971[73] Assignee Westinghouse Electric Corporation Pittsburgh, Pa.

[54] CODED SIGNAL TRANSMISSION SYSTEM 10 Claims, 2 Drawing Figs.

[52] U.S.Cl 340/168, 340/22, 340/324 [51] Int.Cl G081: 23/00, H04q 9/00[50] Field of Search 340/168, 167,147, 324, 324.1, 22

[56] References Cited UNITED STATES PATENTS 3,300,775 1/1967 Dowling340/168SR v 3,336,587- 8/1967 Brown.... 340/324 3,350,697 10/1967Hirvela... 340/147X 3,307,169 2/1967 340/168X Beck SHIFT REGISTERDIVIDER I LLATOR TRAIN POSITION DETECTOR Primary Examiner-Donald J.Yusko AttorneysF. H. Henson and R. G. Brodahl ABSTRACT: Coded signaltransmission equipment is dis closed wherein a preselected traindestination signal comprising a six-bit code signal coded to correspondto anyone out of 0 to 49 and/or a preselected train length signalcomprising a six-bit code signal coded to correspond to anyone out of 50to 59 are sent between a train vehicle and a selected wayside location.These numbers are the result of the particular coding techniqueemployed. In general it is desired to send two coded signals and toseparate those signals within the signal receiving equipment in a failsafe manner. For this purpose there is provided a wayside located signalreceiving equipment which includes a signal register in which both thedestination signal and the length signal are serially stored and shiftedby a suitable shift control signal. A predetermined logic circuitarrangement is operative with a selected portion of the shift registerto sense when a predetermined one of said signals is stored in saidportion of the register to indicate that the register at that time isfully loaded and properly oriented. The desired coded signals can thenbe read out and utilized to indicate the train destination and/or thetrain length as may be desired.

A similar technique is employed to transmit coded vehicle performancesignals back to the train vehicle.

TO SUCCEEDING REGISTER ENABLE SUCCEEDING REGISTER PATENTEDJUN Han3,582,894

SHEET 1 0F 2 DISPLAY DEVICE TRANSMITTER ANTENNA REGISTER v BIT SHIFT (ILU 9 2 O F- 2 g Q m g [I O I *5 WITNESSESI- INVENTOR Robert C. HoylerATTORNEY PATEN TED JUN 1 I971 SHEET 2 [IF 2 mokowhuo ZOrEmOm 23;;

mup wwm w l 25 mu :m I

592m Nm 59 6 586mm 3 t 5 556mm $25583 9 v mam CODED SIGNAL TRANSMISSIONSYSTEM BACKGROUND OF THE INVENTION In high speed train vehicle controlapplications there is an important requirement that the train vehicle beidentified at specified wayside locations, such as passenger stations,along its travel route. This can be required for example in relation tothe indication to passengers waiting at the station of the destinationof a particular train vehicle or train of several vehicles, and furthercan be required for the purpose of locating the final stopping positionof a train in regard to the length ofa particular train of vehicles thatis approaching a passenger station. It can be desirable to transmit fromthe train vehicle information consisting of a train destination codesignal, which is received at the wayside location and energizes aparticular passenger monitored display sign for example, and further atrain length code signal. It can be desirable to transmit from thewayside station back to the train certain performance information or thelike for the purpose of causing the train to slow down or to speed upits general response or other similar train control information as maybe desired to be transmitted to the train vehicle.

Because of increasing requirements for high speed transportation,automatic transit systems and train control systems are gaining inimportance and becoming more desirable to solve many of the problemsassociated with these requirements. An automatic train control systemrequires coded signal transmission from the moving train to the waysidelocation, such as a passenger platform, of the particular trainidentification information, consisting of information such as adestination for the train and the length of the train. This willindicate to the passengers where a particular train is going and informthe passengers how much of the length of a platform will be occupied bythe particular train which is next to arrive. The train identificationinformation is usually carried by the train and transmitted from a traincarried antenna to an antenna associated with the train track andlocated some distance away from the platform, for example a mile, suchthat the train identification information is transmitted and received bythe passenger station equipment a predetermined time prior to thearrival of the train to permit the passengers to have an adequatereceipt of required information to maximize and facilitate the flow ofpassengers onto the train and from the train.

Certain information should be transmitted back to the train to optimizethe operation of the train vehicle in relation to the desired operationof the entire high speed transportation system which is controlled by amonitoring control system. The problem here is to determine whether agiven coded signal that is received from the train vehicle correspondsto the train destination or corresponds to the train length, and toimplement means for effecting the desired transfer of this trainidentification information.

The prior art apparatus for transmitting information from train towayside includes a manual interface using voice or printed informationor automatic optical reading techniques. These methods have thedisadvantages of being either slow and nonautomatic or limited byenvironment. Manual methods are presently the most common means forreturning data to the train itself.

SUMMARY OF THE PRESENT INVENTION In accordance with the presentinvention respective coded signals are assigned to the train destinationand to the train length, such as a six-bit signal corresponding to to 49for the train destination and a six-bit signal corresponding to 50 to 59is assigned to the train length. Thus by determining at the waysidewhether a received coded signal is numerically greater or less than 50it can be determined which coded signal has been sent in a particulartime interval. Since both coded signals are sent together'and seriallyfrom the train to the wayside, the present invention permits properalignment of the two coded signals in a single station receiver registerapparatus.

The train destination coded signal is stored in a first register on thetrain and continuously transmitted from the train while the train ismoving. This is done by transferring it in parallel to a secondregister, operative as a shift register, which then transmits itserially from the train, through a train carried transmitter andantenna, and couples the so transmitted signal into a wayside locatedantenna operative with the wayside signal receiving equipment.

In accordance with the general operation of the train movement controlsystem, the train vehicle receives a six-bit comma free coded signal forspeed control, from which common word and bit rates may be derived tosynchronize this identification signal transmission operation on boththe train and at the wayside.

As an example of suitable comma free coded trainspeed control signals,the following are suitable six-bit signals for this purpose:

l0] 1 ll 8O m.p.h. lOOl ll 70 m.p.h.

l000l l 50 m.p.h.

l0l0l l 34 m.p.h.

b 100101 27 mph.

lOlOOl 18 m.p.h.

l00000 l2 m.p.h.

l0000l 6 m.p.h.

l0l000 0 m.p.h.

At points along the track where this information is needed from thetrain, such as passenger station locations, an antenna of sufficientlength to pick up at least 12 serial bits of coded identification signalinformation from the train, at the top train speed of miles per hour, isplaced along the track. These signal bits are detected and stepped intoa circulating [2-bit shift register synchronized to the common word andbit pulse rates. Once the register has accepted l2 bits of coded signalinformation, no matter which signal bit in the cycle was first received,the complete signal information will continue to circulate within theregister at the bit rate even if the input to the register is removeddue to the train carried antenna being no longer coupled to the waysidelocated antenna.

The presence of a number greater than 50 stored in the last section ofthe shift register at any work pulse time indicates the register to befully loaded and to be properly oriented. This sets a control flip-flopwhich removes the input connection and removes the shift signal from theshift register, and at this time the length and destination codedsignals are properly oriented in the register and can be read out asdesired. As soon as these signals have been read out, the circulatingshift register is reset to zero and enabled to receive a subsequentinformation signal transmission from a succeeding train.

Simple logic circuitry can be provided to switch a succeeding secondshift register onto the input line connection to receive and store asecond information signal transmission while the first information isstill being processed if desired. By adding additional registers in thisway as much storage capability as required can be provided.

In the requirements for one particular system, it is desirable totransmit a third coded signal containing train performance modificationinformation back to the train while the train is stopped at the stationlocation. This is done in essentially the same way, except that theperformance modification information signal must go into a differentregister when received on the train. As before, the coded signal isassigned a numerical value greater than 50 and the signal received onthe train is inspected at word intervals until the signal stored in theproper register section is greater than 50. At this time the input andshift signals are removed from this train carried register and thesignal transmission is complete.

It is an object of the present invention to provide an improved and morereliable coded signal transmission system, which system is betteroperative to effect the desired transmission of one or more codedsignals, such as train identification or control signals, between afirst signal storage apparatus, which can be carried by a trainvehicle,and a second signal storage apparatus, which can be located at a waysideposition with an improved signal coupling being provided for asufficient time interval to permit the completion of said signaltransmission.

BRIEF DESCRIPTION OF THE DRAWINGS In FIG. 1 there is shown the trainvehicle carried equipment, operative for sending the train destinationand train length coded signals to a wayside location such as a passengerstation, divergent point, or the like.

In FIG. 2 there is shown the wayside located logic equipment, operativefor receiving the train destination and train length coded signals.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE PRESENT INVENTION In FIG.1 there is shown a first six-bit register 10 for containing thedestination information of the train in the form of a sixbit code signalcorresponding to a selected one of the numbers to 49. A second six-bitregister 12 more permanently is loaded with the train length informationin the form of a six-bit code signal corresponding to a selected one ofthe numbers 50 to 59. When it is desired to load a destination signalinto the register 10, or a train performance control signal into theregister 11, a suitable start signal is applied to terminal 14 to causea flip-,fiop 16 to change its state of operation such that a high levelsignal is thereby supplied to an input of AND device 18 and AND device20.

In reference to FIG. 1 the start signal applied to terminal 14 is usedonly for the purpose of reading signal information into the six-bitregisters and 11. A first control line 40 supplies an 18 cycle/sec. bitrate signal through the AND gate 20 to shift the register 10 and 11 andapplies through the AND gate 22 a bit rate signal to shift the 12-bitshift register 24. A second control line 43 is operative to supply asix-bit cycle/sec. word rate signal to one input of AND gate 28 andthrough a flip-flop divider 30 to a second input of the AND gate 28 suchthat the AND gate 28 has both of its inputs energized with simultaneoushigh level signals after the occurrence of every other word pulse to atthis time provide an output signal to open the twelve AND gates 32operative with the respective input signal bits of register 24 to allowthe six-bit register l0 and the six-bit register 12 to transfer theirrespective signal contents into the l2-bit shift register 24 upon theoccurrence of every other word rate signal pulse. The start signalapplied to terminal 14 is for the purpose of changing the sixbitdestination signal stored within the bit register 10. The train iscontinuously transferring information from the six-bit registers 10 and12 into the shift register 24 and sending it out through the transmitter33 and antenna 34 in a continuous and repetitive cycle of operation.This signal information is transmitted whenever the train is inoperation whether the antenna 34 is coupled to the wayside antenna andreceiver operative with the station equipment or not. This makesunnecessary the provision of a transmission operation start signal whichis subject to failure. The train is continuously sending its destinationand length information signals and wherever the wayside location desiresthis signal information a receiving antenna can be positioned to pick itup.

When it is desired to change the destination signal stored in the bitregister 10, a suitable start signal is applied to terminal 14 and themodified destination information signal is supplied through theinformation conductor 42 leading to AND gate 18. For this purpose ofsupplying in serial arrangement the six signal bits of desired modifieddestination signal, a predetermined start signal could be supplied tothe train, such as a one second duration signal or a specific codesignal or the like with a suitable signal sensing device in the form ofa predetermined logic circuit that could sense and apply the desiredstart signal to the terminal 14 when it is desired to change thedestination signal stored within the bit register 10. Also, a codedsignal receiver could be provided ahead of the start terminal 14 forthis purpose if desired.

The destination signal information which is read in to modify thedestination signal in the bit register 10 can be one or both of adestination modification signal and performance modification signal.When a start signal is received, the flipfiop 16 is changed in itsoperation to open the AND gates 18 and 20. The train carries a suitablereceiver which can be coupled to a station located antenna for supplyinga destination modification signal and a modified performance signalthrough the conductor 42; these two 6-bit signals are supplied in serialform with the modified performance signal being supplied first and beingnumerically between 50 and 59 and with the destination signal beingsupplied second and being numerically between 0 and 49, such that after12 bits of signal information have rippled through the AND gate 18 intothe six-bit register 10 and the six-bit performance register 11, thelogic circuitry including the OR gate 13 in conjunction with the ANDgate 15 senses the storage within the performance signal register 11 ofthe modified performance signal, which is greater than 50 such that theAND gate 15 provides an output signal to the flip-flop 16 to change itsoperation such that the AND gates 18 and 20 no longer pass signalinformation and shift signals respectively through to the register 10and the register 11. With the AND gates 18 and 20 closed, this preventsundesired noise signal pulses from entering the registers 10 and 11.Thusly whenever it is desired to change the performance signal, it alsochanges the destination signal or at least the storage of thedestination signal, because the performance modification signal mustfirst pass through the destination signal register 10 in order to enterthe performance signal register 11, after which the same or a differentdestination signal is again entered into the destination signal register10.

In general the performance signal controls the acceleration rates of thetrain or determines that the train vehicle go faster or slower or asimilar control function. The performance signal determines that thespeed be decreased by 5 percent or by 10 percent or decrease theacceleration rate by 5 percent or 10 percent in an effort to optimizethe operation of the train. A central control computer can be programmedto monitor the train operation and provide this performance modificationinformation if it notices that the train vehicles in a particularlocation of the system are beginning to bunch up or some obstruction hasoccurred on the track or something of this type. When the train vehiclesbunch up on the track, it is desired that the last ones be slowed downto open up the spacing between the vehicles and if suitable the firstvehicle should be increased in speed to open the spacing between thevehicles.

The performance signal is differentiated from the destination signal byassigning to the performance signal a numerical value between 50 and 59and by assigning to the destination signal a numerical value between 0and 49. This permits us to sense through the OR gate 13 and AND gate 15that the numbers stored within the performance signal register 1 l isgreater than 50 and therefore it is the performance signal; further whena number having a numerical value greater than 50 is stored within theperformance signal register 11, this informs the control apparatus thatthe signal transmission to change the performance signal and/or thedestination signal has been completed, such that the flip-flop 16 shouldbe changed in its operation to now close the AND gates 18 and 20. Itshould be understood that the performance signal stored within theperformance signal register 11 is then utilized for controlling thetrain propulsion equipment as should be readily apparent to personsskilled in this art for the purpose of controlling the movement of thetrain vehicle. An alternate way of providing the modified performancesignal would be to utilize a train carried local signal generator, otherthan the signal receiver previously described, which would enable anoperator on the train to change the performance signal stored within aperformance signal register 11 and/or the destination signal storedwithin the destination signal register 10 if this were desired. Thel8-cycle/sec. bit rate signal from the control line 40 is appliedthrough the AND gate 22 to shift the l2-bit register 24 to continuouslysupply in a serial manner the respective destination and length codesignals to a transmitter 33 and antenna 34 while the train is in motion.It is thus seen that the AND gate 28 provides an output signal to openeach of the respective AND gates 32 and effects a transfer in parallelfrom the two 6-bit registers and 12 into the 12-bit shift register 24,which then is operative to sequentially shift the individual bits to thetransmitting antenna 34 in accordance with the 18- cycle/sec. bit ratesignal from the control line 40. The 3-cycle/sec. word rate signal fromthe line 43 and the l8-cycle/sec. bit rate signal from the line 40synchronize the train identification signal transmission on the trainand a similar signal synchronization controls the receiving of thesesignals by the wayside station.

In FIG. 2 there is shown the wayside located equipment used forreceiving the train destination and train length coded signals at pointsalong the train movement path where this information is needed, such asat passenger stations, and the like. A receiving antenna 60, ofsufficient length to pick up at least the 12 bits of signal informationserially transmitted from the moving train, is suitably placed along thetrain track. The train transmitted signals are picked up, amplified, andpassed to one input of an AND gate 62 which has its second inputenergized from the conductor 64 from the flip-flop 66 which at this timeprovides a high level output signal to the conductor 64. The received 12bits of signal information pass through the AND gate 62 and the OR gate68 into a 12-bit shift register 70. The operation of the latter register70 is synchronized to the 3-cycle/sec. common word and l8-cycles/sec.bit rate pulses received from the respective control lines 73 and 74,which same word rate and bit rate pulses are provided on the train. Oncethe shift register 70 has accepted the l2 bits of coded signalinformation, no matter which bit in the cycle is first received, thecomplete 12 bits of signal information will continue to circulatethrough operation of the conductor 72 as shifted by the l8cycle persecond bit rate signal -cycle over the conductor 74 to AND gate 76 whichhas its second input energized by the high level output signal from theflip-flop 66, such that each bit rate signal from the control line 74passes through the AND gate 76 and is effective to shift by one bit thesignal stored within the shift register 70. With the provision of theconductor 72 connected through the OR gate 68, when the train suppliedsignal from the receiving antenna 60 is removed, the complete 12 bits ofsignal information stored within the shift register 70 will continue tocirculate at the bit rate frequency. The presence of a stored numbergreater than 50 in the last half section of the register 70 at a wordpulse time is sensed by the logic gates 80 and 82 and indicates theregister is fully loaded and is properly oriented. For this purpose theAND gate 80 is connected to respond to the binary 32 stored in thesixth-bit position and the binary l6 stored in the fifth-bit position ofthe second half of the shift register 70; through the OR gate 82 any oneof the binary eight-bit position, the binary four-bit position or thebinary two-bit position also energizes the AND gate 80 such that thesixth-bit position and the fifth-bit position provides a total count of48, and any one of the other binary bits operative through the ORcircuit 82 will cause the AND gate 80 to sense a stored signal withinthe last six stages of the shift register 70 of a value greater than 50.This sets the flip-flop 66, which now removes the high level signalsupplied to the conductor 64 and this will block the AND gate 62 andblock the shift pulses supplied through the AND gate 76. At this timethe destination code signal and the length code signal are stationaryand properly aligned in the register and can be read out as required.For example a suitable signal reading device 84 can be responsive to thelength code signal stored within the six stages of the last half of theshift register 70, and a signal reading device 86 can be connected toindicate the destination code signal stored within the six stages of thefirst half of the shift register 70. Suitable display devices 88 and 90in the form of respective signs or the like can be provided to indicateor further utilize as desired the destination code signal and the lengthcode signal so determined. As soon as these signals have been read andutilized, the circulating shift register 70 is reset to zero by forexample a manual switch or a train position detector which can beenergized when the train leaves the station platform and provides asignal to reset the shift register 70 and to reset the flip.- flop 66.

The antenna and receiver 60 shown in FIG. 2 may be located up to a miledown the train track ahead of the station location at which is providedthe apparatus shown in FIG. 2.

If desired, suitable logic circuitry could be provided to switch anothershift register similar to register 70 onto the input line connected tothe receiving antenna 60 to receive and store a subsequent signaltransmission from a succeeding train while the first transmission isstill being processed by the shift register 70. By adding additionalregisters in this way as much signal storage capacity as required can beprovided. The high level output signal from the flip-flop 66 and appliedto conductor 92 could be utilized to control the enabling of thesesucceeding registers as desired.

ln the requirements for one particular train control system. for whichthis equipment was applied it was necessary to transmit from a passengerstation location back to the train another multiple bit coded signalcontaining a performance modification to tell the train to do a selectedone of increase its speed or decrease its speed and/or change itsacceleration patterns or the like; the latter signal transmission canoccur while the train is stopped at the station platform. This signaltransmission back to the train is done in substantially the same way andwith generally similar equipment as previously described in relation tothe train length and train destination signals, with the modificationsignal going into its own and separate register 11 as shown in FIG. 1when received on the train. The modification signal received on thetrain is inspected at word intervals until the signal in the register 11is greater than 50. At this time the input and shift signals are removedfrom the train carried registers and the signal transmission process iscomplete. The performance modification signal can then be read andutilized aboard the train as desired.

Some advantages of the present system over prior art existing systems isthat it is bidirectional in operation, completely automatic, independentof environment, compatible with the signalling and synchronization inthe here accompanying train control system, and the signal informationcan be easily modified as requiredThis latter signal modification couldinclude a change in stored information as well as a change in the typeof information sent. At the present time there is a need for the presentsignal transmission apparatus to send and receive train identificationsignals as a part of an overall train control system or, transmit thisinformation as an ordered sequence in a two word distribution.

For a description of one suitable train control system with which thepresent coded signal transmission system is operative, see an articleappearing in Railway Signaling & Communications magazine for Dec. 1967at pages 18 to 23 and entitled The BARTD Train Control System by W. P.Bollinger.

While the present invention has been described with a certain degree ofparticularity it should be understood that various modifications andchanges thereof will be readily apparent and can be made within thescope and spirit of the present invention.

1 claim as my invention: 1. in a signal transmission system includingfirst equipment for transmitting a predetermined signal comprising aplurality of binary bits, and second equipment for receiving saidsignal, the combination of:

first signal storage means associated with said first equipment forstoring said signal before said first equipment transmits said signal; 7

second signal storage means associated with said second equipment forstoring said signal after the signal has been transmitted and isreceived;

signal coupling means operative for at least a predetermined timeinterval to couple said signal for transmission from said firstequipment to said second equipment;

and signal responsive means operative with one of said signal storagemeans for responding to a storage of at least a given number of saidplurality of binary bits in a predetermined location within said onesignal storage means to control the time interval during which saidsignal coupling means is operative.

2. The signal transmission system of claim 1,

with said signal including a first portion and a second portion, saidsecond portion being numerically different than said first portion,

and with said given number of said plurality of binary bits beinglocated in said second portion of said signal for determining thelocation within said one signal storage means where said given number ofbinary bits are stored.

3. The signal transmission system of claim 1, with said signal includingat least one multiple bit word of information, and control means forsensing the rate of bit transmission by said system,

said one signal storage means comprising a shift register for storing atleast one word of information and being operative with said controlmeans for shifting the bits of said one word through said shiftregister,

and said signal coupling means being operative to receive serially theso shifted bits of said one word from said shift register 4. In a codedsignal transmission system operative with at least one predeterminedsignal having a plurality of bits, the combination of:

first signal means for storing said coded signal and including a firstshift register into which said coded signal is fed; signal couplingmeans for removing said coded signal from said first signal means;

second signal means for storing said coded signal and including a secondshift register operative with said signal coupling means for receivingsaid coded signal from said first signal means;

control means operative with at least one of said shift registers forcirculating said coded signal within at least said one shift registeruntil there occurs a predetermined arrangement of said bits; and

means responsive to the predetermined arrangement of said bits withinsaid one shift register and operative with said signal coupling meansfor transmitting said coded signal from said first signal means to saidsecond signal means during the interval of time said predeterminedarrangement of bits occurs.

5. The signal transmission system of claim 4,

with said first signal means including a signal register for initiallystoring a coded signal to be periodically transmitted to said firstshift register;

and means for shifting said coded signal through said first shiftregister to said signal coupling means in a serial bit by bit manner.

6. The signal transmission system of claim 5, including shift signalmeans providing a bit rate control signal determined by the signaltransmission bit rate of said system for shifting the coded signalstored in said second shift register at said bit rate,

and signal indication means operative with said second shift registerand responsive to said coded signal stored in said second shift registerfor indicating the completion of said coded signal transmission. 7. In asignal transmission system including a first station for transmitting asignal comprising a plurality of binary bits and a second station forreceiving said signal, the combination comprising:

first signal storage means operative with said first station for storingsaid signal for a first given amount of time before said first stationtransmits said signal; second signal storage means operative with saidsecond station for storing said signal for a second iven amount of timeafter the signal has been transmrtte by said first station and receivedby said second station;

signal coupling means operative during time intervals, which may bedifferent in length of time from one interval to the next, for couplingsaid signal for transmission from said first station to said secondstation; and

signal responsive means operative with said first signal storage meansfor responding to a storage of at least a given number of said pluralityof binary bits in a predetermined location within said first signalstorage means to control the time interval during which said signalcoupling means is operative.

8. The signal transmission system of claim 7, with said first signalstorage means comprising:

a first shift register which receives at least a portion of said signalto be transmitted;

a second shift register connected in series with said first shiftregister such that said signal may be recirculated through said firstand second registers; and

a third shift register connected to said first shift register to receivethe signal stored in said first shift register, said third shiftregister being connected to said signal coupling means.

9, The combination claimed in claim 8, with said signal responsive meanscomprising:

at least one gate having a plurality of input terminals and an outputterminal, said plurality of input terminals being connected in apredetermined arrangement to said second shift register for producing aset pulse at said output terminal in response to the storage of at leastsaid given number of said plurality of binary bits in said predeterminedlocation in said second shift register;

A flip-flop having a set terminal and an output terminal, said setterminal being connected to the output terminal of said one gate forreceiving said set pulse and producing in response thereto a shiftsignal at said output terminal of said flip-flop; and

means for applying said shift signal to said third shift register fortransmitting said signal from said third shift register to said signalcoupling means.

10. The combination claimed in claim 9, with said second signal storagemeans comprising:

a fourth shift register connected to said signal coupling means forreceiving and storing said signal; and

means responsive to the storing of said signal for displaying saidsignal.

1. In a signal transmission system including first equipment fortransmitting a predetermined signal comprising a plurality of binarybits, and second equipment for receiving said signal, the combinationof: first signal storage means associated with said first equipment forstoring said signal before said first equipment transmits said signal;second signal storage means associated with said second equipment forstoring said signal after the signal has been transmitted and isreceived; signal coupling means operative for at least a predeterminedtime interval to couple said signal for transmission from said firstequipment to said second equipment; and signal responsive meansoperative with one of said signal storage means for responding to astorage of at least a given number of said plurality of binary bits in apredetermined location within said one signal storage means to controlthe time interval during which said signal coupling means is operative.2. The signal transmission sysTem of claim 1, with said signal includinga first portion and a second portion, said second portion beingnumerically different than said first portion, and with said givennumber of said plurality of binary bits being located in said secondportion of said signal for determining the location within said onesignal storage means where said given number of binary bits are stored.3. The signal transmission system of claim 1, with said signal includingat least one multiple bit word of information, and control means forsensing the rate of bit transmission by said system, said one signalstorage means comprising a shift register for storing at least one wordof information and being operative with said control means for shiftingthe bits of said one word through said shift register, and said signalcoupling means being operative to receive serially the so shifted bitsof said one word from said shift register.
 4. In a coded signaltransmission system operative with at least one predetermined signalhaving a plurality of bits, the combination of: first signal means forstoring said coded signal and including a first shift register intowhich said coded signal is fed; signal coupling means for removing saidcoded signal from said first signal means; second signal means forstoring said coded signal and including a second shift registeroperative with said signal coupling means for receiving said codedsignal from said first signal means; control means operative with atleast one of said shift registers for circulating said coded signalwithin at least said one shift register until there occurs apredetermined arrangement of said bits; and means responsive to thepredetermined arrangement of said bits within said one shift registerand operative with said signal coupling means for transmitting saidcoded signal from said first signal means to said second signal meansduring the interval of time said predetermined arrangement of bitsoccurs.
 5. The signal transmission system of claim 4, with said firstsignal means including a signal register for initially storing a codedsignal to be periodically transmitted to said first shift register; andmeans for shifting said coded signal through said first shift registerto said signal coupling means in a serial bit by bit manner.
 6. Thesignal transmission system of claim 5, including shift signal meansproviding a bit rate control signal determined by the signaltransmission bit rate of said system for shifting the coded signalstored in said second shift register at said bit rate, and signalindication means operative with said second shift register andresponsive to said coded signal stored in said second shift register forindicating the completion of said coded signal transmission.
 7. In asignal transmission system including a first station for transmitting asignal comprising a plurality of binary bits and a second station forreceiving said signal, the combination comprising: first signal storagemeans operative with said first station for storing said signal for afirst given amount of time before said first station transmits saidsignal; second signal storage means operative with said second stationfor storing said signal for a second given amount of time after thesignal has been transmitted by said first station and received by saidsecond station; signal coupling means operative during time intervals,which may be different in length of time from one interval to the next,for coupling said signal for transmission from said first station tosaid second station; and signal responsive means operative with saidfirst signal storage means for responding to a storage of at least agiven number of said plurality of binary bits in a predeterminedlocation within said first signal storage means to control the timeinterval during which said signal coupling means is operative.
 8. Thesignal transmission system of claim 7, with saiD first signal storagemeans comprising: a first shift register which receives at least aportion of said signal to be transmitted; a second shift registerconnected in series with said first shift register such that said signalmay be recirculated through said first and second registers; and a thirdshift register connected to said first shift register to receive thesignal stored in said first shift register, said third shift registerbeing connected to said signal coupling means.
 9. The combinationclaimed in claim 8, with said signal responsive means comprising: atleast one gate having a plurality of input terminals and an outputterminal, said plurality of input terminals being connected in apredetermined arrangement to said second shift register for producing aset pulse at said output terminal in response to the storage of at leastsaid given number of said plurality of binary bits in said predeterminedlocation in said second shift register; A flip-flop having a setterminal and an output terminal, said set terminal being connected tothe output terminal of said one gate for receiving said set pulse andproducing in response thereto a shift signal at said output terminal ofsaid flip-flop; and means for applying said shift signal to said thirdshift register for transmitting said signal from said third shiftregister to said signal coupling means.
 10. The combination claimed inclaim 9, with said second signal storage means comprising: a fourthshift register connected to said signal coupling means for receiving andstoring said signal; and means responsive to the storing of said signalfor displaying said signal.